1. Field of the Invention
The present invention relates to an image generation system and more particularly, relates to an image generation system switching between dual-wavelength lasers, outputting the laser to an optical filter and generating an ultrasound image and a photo-acoustic image of an object by a photo-acoustic effect.
2. Description
The technique of generating images by means of ultrasound has been widely adopted in biomedical applications. Compared with other medical imaging systems such as X-ray, computed tomography (CT), magnetic resonance imaging (MRI) and nuclear medicine imaging utilized in clinic, ultrasonic imaging has advantages of cost effectiveness, non-invasiveness, no ionizing radiation, real-time imaging capability, high spatial resolution (less than 1 millimeter), portability, flow estimation ability, etc. Thus, ultrasound imaging has been commonly applied to clinical diagnosis in several medical categories.
Apart from ultrasound imaging, the photo-acoustic effect has also been utilized in imaging; photo-acoustic effect means when an object is exposed to light, the object absorbs the energy of light and then thermal expansion effect happens within a short period of time; sound waves are thus generated. One purpose of photo-acoustic imaging is to show the distribution of optical absorption of the object by receiving the sound waves.
At present, both ultrasound imaging and photo-acoustic imaging utilize a receiving device in an ultrasound probe to receive sound waves for subsequent image processing. However, due to some clinical and medical needs, making probes more compact and smaller has been an important development task. For example, the need for endoscopic and intravascular imaging has been a driving force to develop miniaturized ultrasound probes.
When developing miniaturized probes for ultrasound imaging, piezoelectric materials such as Lead Zirconate Titanated (PZT) are often used. However, when it comes to miniaturization, it is very difficult to cut ceramic piezoelectric materials. Meanwhile, crosstalk interference is more likely to happen which makes developing miniaturized probes more difficult.